Iso-alkyl resorcinol



Patented Nov. 15, 1927.-

UNITED STATES mates rarest OFFICE.

ALFRED R. L. IDOHME, OF BALTIMORE, MARYLAND, ASSIGNOR TO SHARP & DOHME,

me, or BALTIMORE. MARYLAND,

A GOEPQRATION OF NEW JERSEY.

I ISQ-ALKYL BESORGI'NQL.

No Drawing".

The present invention relates to new isoalkyl resorcinols of thefollowing general formula, C H (OH) R, where R is an isoalkyl grouphaving more than 3 carbon atoms. The invention includes such iso-alkylresorcinols as iso-butyl, iso-amyl, isohexyl resorcinols, etc.

The invention includes the compounds in a pure state as well as in apartially purified state.

The new iso-alkyl resorcinols may be prepared by the reduction of thecorresponding iso-acyl resorcinols with a reducing agent, such as, forexample, zinc amalgam and hydrochloric acid, followed by purification byredistillation in vacuo, recrystallization from solvents, etc.

The new iso-alkyl resorcinols may also be produced from resorcinol andthe correspending iso-fatty acids by causing the acid and the resorcinolto react in the presence of the condensing agent, such as zinc chloride,at elevated temperatures, forming the intermediate ketone, thatis, theiso-acyl res sorcinol, which is then purified to a greater or lessextent and reduced to form the isoalkyl resorcinol, using a suitablereducing agent, such as, for example, zinc amalgam and hydrochloricacid.

The tollowing specific examples, which relate to the production ofiso-butyl resorcinol, will illustrate methods of preparing the newiso-alkyl resorcinols. v

Preparation of iso-butyl resorcinol from iso-butyryl resorcinol: 1 partof iso-butyryl resorcinol is reduced by 2 parts zinc amalgam in 5 partsof hydrochloric acid (20 Be.)

and 6 parts of water, with vigorous stirring at 105 C. The reduction iscomplete in about 10 or 12 hours. The reduction product is washed withan equal volume of water and the water layer separated. The reductionproduct is then distilled in vacuo whereby the last traces of water areremoved and finally the iso-but l resorcinol is distilled. The productis t on redistilled, the distillate permitted to solidify into a solidand the'solid is recrystallized from a mixture of toluene and petroleumether, yieldin white crystals which have a meltingfpoint 0 about 62-63.5C. 'Iso-butyl resorcinol has a boiling point of about 166168 at 6-7 mm.

Iso-but l resorcinol may also be produced in a sing e process fromresorcinol and isobutyric acid, as follows Twenty parts of Applicationfiled April 29, 1925. Serial No. 26,814.

anhydrous zinc chloride are dissolved in 100 parts of iso-butyric acid,the solution being aided by heatingand stirring. Thirty-three parts ofresorcinol areraduallv added over a period of about 20 minutes while thetemperature is maintained near 135 C. and the reaction mixture is thenstirred for a period of about 3 hours in a temperature of about 135 to145 C. At the end of this time an equal volume of water is added and themixture is further stirred. The oily reaction product rises to thesurface, is separated from the aqueous layer, and washed with an equalvolume of water and the water then separated from the washed product.The productis'then distilled in vacuo, traces of water and the excessiso-butyric' acid bein first distilled over and finally the iso-butyrresorcinol being distilled ove'r...The distillate can then be subjectedto reduction, without isolation of the pure iso-butyryl re sorcinol, bytreating it as abovedescribed.

The iso-butyryl resorcinol may be further purified by redistillation andcrystallization from a mixture of toluene and petroleum ether. Afterredistillation and crystallization the product is inithe form of whitecrystals having a melting point of about 67-68.5 C. The iso-butyrylresorcinol has a boiling point of about 173175v C. at 6-7 mm. pressure.

The pure crystals of iso-butyryl resorcinol may also be reduced asdescribed above. It is not necessary, however, to isolate theiso-butyryl resorcinol in a pure crystalline state, but the partiallypurified product, as distilled off from the reaction mixture, may bedirectly reduced, as describedabove.

In a similar manner other iso-alkyl .resorcinols, such as the iso-amyl,iso-hexyl, etc. I resorcinols, may'be produced, either from thecorresponding iso-acyl resorcinols, or directly in a single process fromresorcinol and the corresponding iso-fatty acid. Amon the new iso-alkylresorcinols so obtainab e may be mentioned the following, the meltingpoint and boiling point of each compound in a purified state eing given:

3. Anew product comprisin iso-butyl resorcinol having the followingormula,

, /UH: CIHJ(OE)rt-QH\OH; 4. As a new product pure iso-butyl resorcinolhaving the following formula,

' cimomr-om-onfig', being a white crystalline solid having a meltingpoint of 6263.5 C. and healing at 166168 C. at 6-7 mm. pressure.

In testiu ony whereof I afiix m signature.

ALFRED R. L. OHME.

